Perseus was visited by Hermes who gave him winged shoes and told him the directions to the Gray Sisters so that he can ask them where the Nymphs of the West are.
Perseus flew over to the Gray Sisters and stole the eye and the tooth that all three of them shared. He then demanded that they told him the location of the Nymphs or he would destroy the eye and the tooth. The sisters gave in and told Perseus the location of the Nymphs
Perseus meets the Nymphs of the West (Atlas's daughters) and they lead him to where the sword and Helmet of Darkness are so that he could use them against Medusa. Since the Nymphs thought that he was hot, they begged him to come back. He promised that he would come back soon.
Following the nymphs directions, Perseus flies to where the Gorgans live. He enters the cave to find all three sisters sleeping, using his shield as a mirror to make sure that he doesn't turn into stone, he goes over to where Medusa is sleeping. He cuts off her head, killing her. Because she was pregnant her children popped out once Perseus killed her, one of them was Pegasus and the other was Chrysaor.
When Perseus cut off Medusa's head, her sisters woke up and tried to catch up with him. Their wings were clashing together trying to catch up withPerseus but they couldn't.
Perseus was so overjoyed from slaying Medusa that he decided to fly back to where the Nymphs of the West were so that he could party with them .